Computer and communication technologies have provided many opportunities for developing transaction methods such as credit cards, debit cards, and electronic fund transfers. Many of these involve encryption of messages which authorize, acknowledge and/or allow the transfer of funds upon validation by the owner of the funds. This has provided new methods of conducting conventional transactions consisting of a reciprocal exchange of currency for goods/services. These methods allow a third party to engage in the currency exchange aspect of the transaction. None of these however addresses the validation of the goods/services for which the currency is exchanged for a party not present at the transaction. This creates limitations on the flexibility of the types of transactions that can be performed and the reliability of transactions that might be performed.
In another well established approach in which three parties are involved in a transaction, a special currency (i.e. food stamps) is given directly by one party (a government agency) to the another party (a citizen), this special currency is used to receive a benefit (food) from a third party provider (a supermarket), and then is redeemed for legal tender. While this approach enables validation of the benefit under conditions of a reliable provider, it does not validate the recipient, enabling abuse. Newer systems involving payment cards with personal identification numbers only partly address this and other limitations.
There are other ways in which multiple parties can engage in transactions in which the parties are separated by space, or by scheduling constraints and communication between the parties are limited. Examples of such transactions would include: 1) charity or philanthropic organization A providing funds to service organization B which in turn provides services to an individual or a population C, and 2) party A providing tokens to party B that can be redeemed only for a predetermined set of goods or services at a predetermined time, such as gift cards.